This is the power of education. And this is what drives UNICEF's efforts to bring it to children who are most at risk of being left behind — children who are fleeing conflict or facing famine. Children who are forced to work, and girls who are forced to marry.

In 2016 alone, UNICEF spent $1 billion on education programs globally, with 700 experts working in 155 countries. Through these efforts, UNICEF provided learning materials and other support to 15.7 million children, including 11.7 million children affected by war, natural disasters and other humanitarian emergencies.

UNICEF's Education in Emergency initiative provides safe spaces and educational materials to help displaced and refugee children who have been forced out of school get back to learning.

But it's not enough. Despite the gains, an astonishing number of children and adolescents — 264 million worldwide — are out of school, missing out on the education they need to reach their full potential.

In South Sudan, for example, many schools have closed, and teachers have fled, along with 3.4 million other people as a result of the ongoing war. UNICEF's Education in Emergency initiative provides safe spaces and educational materials to help displaced and refugee children who have been forced out of school to get back to learning. Education is central to the overall humanitarian response, a way of restoring hope and normalcy for children who have been uprooted and traumatized.

In Somalia, where famine looms as a result of a severe drought, displacing families and endangering young lives, UNICEF is providing clean, safe water to schools in addition to other emergency relief to help keep kids enrolled.

In Syria, six years of violent conflict, social upheaval, and loss of family income have pushed 1.75 million children out of school. Many children, on the run with their families since birth, have never been to school at all. It is particularly challenging for UNICEF to reach children in areas that remain under siege. Some children are making do with makeshift classrooms and volunteer teachers. In 2016, UNICEF supported more than 327,000 children who are learning in these informal settings.

Some children in Syria have been able to return to their old schools. After repairs were made with UNICEF's help, 23 primary schools in Aleppo were able to reopen their doors to 6,500 students earlier this year. In addition to school rehab efforts, UNICEF was able to reach nearly 3 million school children with "back-to-learning" supplies over the last year.

And in Iraq, where multiple overlapping humanitarian crises have devastated the country's education system, nearly 3.5 million children are no longer learning, or learning very little. In the first half of 2017, UNICEF was able to reach more than half a million children, including more than 240,000 girls, with educational supplies; helped rehabilitate more than 200 schools in Mosul; and built pre-fab temporary spaces serving more than 30,000 — still, reaching only a fraction of those in need.

There is a lot more work to be done. Please support UNICEF's work to educate children around the world.